1. Field of the Invention
This invention relates to storage and shipping containers, and in particular to a container for storing and shipping flat sheets or panels vertically oriented on edge in a horizontal stack, and especially glass lites.
2. Discussion of the Prior Art
Sheets, and in particular glass sheets, often referred to as lites, are oftentimes shipped in horizontal stacks, in which a number of lites are vertically oriented on edge. Particularly for lites, there is a very low co-efficient of friction between adjacent lites, so the horizontal stack tends to rack transversely, i.e. to go from a rectangular or slightly trapezoidal cross-section to being more trapezoidal. Once racking begins, it is difficult to stop, the effects of gravity being what they are.
Containers for such horizontal stacks have typically supported at least one wall of the container vertically so as to prevent the stack from racking and ultimately falling over. Such a container is disclosed, for example, in U.S. Pat. No. 4,467,922 issued Aug. 28, 1984. In this container, a vertical back wall is secured upright to a horizontal base and reinforced in position by diagonally running elongate tension members, to keep the back wall from falling backward. The lites extend above a lower container section which encircles the horizontal stack. The base is a pallet so it can be handled by mechanized handling equipment. The containers can be stacked one on the other, with the upper pallets supported on top of the glass lites in the lower containers.
Since some sheet materials such as glass, ceramics or glass ceramics can be easily chipped or broken, it is desirable to give a high degree of protection from outside forces or completely enclose a stack of such sheets in the container. It is also desirable that multiple containers, although they can be very heavy, can be stacked one on top of the other, and it is desirable that the containers can be handled by a variety of mechanized or automated handling equipment, such as either a forklift truck or an overhead wire rope or chain sling. In addition, the container should provide support against racking of the stack either frontward or backward, and so that the container maintains a substantially rectangular parallelepiped shape.